In our current cultural fascination with the idea of alien beings from
other worlds, most of it hokey at best and just plain wrong at worst,
there is a definite need for some popular-level literature which helps
to sort the rational wheat from the pseudoscience and Hollywood chaff.

Seth Shostak, Public Program Scientist at The SETI Institute in
Mountain View, California -- where they conduct Project Phoenix -- has
created such a book. Titled Sharing the Universe, Shostak gives a
comprehensive and most readable survey of what we do (and especially
do NOT) know about life beyond the planet Earth, and how we are going
about searching for our fellow inhabitants of the Universe.

Whether realized or not, most of the general public gets its
"education" on science, history, and foreign cultures from the films
and television programs they watch.

This is why physicists such as Lawrence M. Krauss write popular books
using the series Star Trek and other science fiction programs to
explain why most of the "science" and technology they present is
either physically impossible or unobtainable for the foreseeable
future.

Many people do come away from science fictions films thinking that
evil alien monsters are waiting to pounce on Earth or that starships
equipped with "warp" drives will be zipping us around the Milky Way
galaxy in the next few centuries. As for the latter, I do hope we are
exploring the interstellar realm by the era Star Trek is set in.
However, unless there is some major breakthrough in physics and
technology, I do not think Scotty will be fixing the mythical
dilithium crystals on the Enterprise to give us Warp 8 to Alpha
Centauri any time soon.

In each chapter of Sharing the Universe, Shostak usually starts off by
presenting some relevant aspect of a popular science fiction film or
series and then showing why it probably would not happen that way in
reality. I was pleased to see that Shostak did his homework when
describing his representative science fiction. While some scientists
may prefer that these forms of entertainment were not interwoven with
serious science, Shostak realized that the public generally does not
discriminate between what Hollywood puts on the screen and what
biological evolution could actually produce on worlds circling distant
suns.

For those who are concerned that Sharing the Universe is little more
than knocking down bad Hollywood aliens and science, put those fears
aside. Shostak gives clear and interesting explanations on the latest
data we have about astrobiology in all its forms.

He starts off with our current understanding about possible life
havens in our own solar system, then works his way into the galaxy
with the new planets being discovered around other stars. Current
thinking is that since we developed on a planet circling a sun, then
other life forms may have done the same. Finding other solar systems
(though so far none quite like ours) is a hopeful step in the right
direction.

The next chapters explore how alien life forms, especially the
intelligent ones, might be created and evolve, and their possible
behaviors. Shostak focuses on the public's major fascination with
aliens who want to find and interact with us. The author deftly shows
how most of the aliens portrayed in our entertainment are far more
mundane and human than they may first appear to be, no matter how many
tentacles or other appendages they might have. Real ETI may be very
different from us in almost every way. Evolution does not always role
the same dice twice, especially on worlds in distant star systems.

The aliens from Hollywood and abduction reports also show just how
socially egocentric humans can be, probably because we have been
isolated on just one planet for most of our existence with no other
intelligent species to compare ourselves to. They assume that every
star-faring race in the galaxy thinks that Earth is the hottest spot
to visit in the heavens, either to save humanity from its primitive
ways or to knock us out of the competition for survival of the
galactic fittest.

More than likely, if ETI do exist, they are completely unaware of
humanity and Earth, as the Milky Way galaxy is so vast and abundant
with billions of stars, planets, nebulae, and other celestial objects.

Even if they do know about us, why would they want to expend so much
of the time, energy, and resources necessary to mount a long and
dangerous interstellar expedition to gather information and materials
from Earth? They can probably find almost anything they want in major
abundance throughout the rest of our vast galaxy, much of it likely
without any current inhabitants.

Of course if ETI want to find and learn about humanity through
interstellar means of communication, that is another matter. Sending
messages through the galaxy is a practical and inexpensive endeavor.
Best of all, we can actually search for these signals right from our
own planet with current technology!

The final chapters discuss how real SETI programs are conducted, what
we may expect if ETI are trying to signal us, how humanity might react
to the discovery, and what kind of responses we should send. Though
the main focus is on Microwave (radio) SETI, other methods, such as
Optical SETI (detecting laser and infrared transmission beams) are
discussed. Since we do not know how ETI might communicate with each
other or us, it is only prudent to utilize all the practical detection
means at our disposal to ensure success.

Shostak answers the people who think that The Government or various
SETI programs have already found that ETI exist and are hiding
evidence of these aliens from the public to avoid a cultural shock and
panic. Shostak relates the story of how one perceived detection
incident with Project Phoenix in June of 1997 -- which turned out to
be the signal from the SOHO solar satellite -- was unintentionally
leaked to the press within twelve hours after the signal was first
found. People just could not keep their mouths shut about what might
have been the most important event in human history.

If a genuine ETI message had been discovered, no doubt by now human
nature would have spread the word across our planet, regardless of any
restriction attempts. And considering how a real first find would
boost the professional and personal lives of the folks who found it,
why would they want to sit on such a gold mine once its authenticity
had been determined?

In summation, I highly recommend Shostak's Sharing the Universe to
anyone who wants the clear and exciting scientific picture of our long
search for other minds in the Cosmos. I also recommend this book for
those who are familiar with the subject, as it can serve as both a
refresher and a guide when someone asks about the latest UFO report or
if that latest alien species on Star Trek could really exist.

My only recommendation for the next edition (and I will presume this
event, as new knowledge in the field keeps growing by leaps and
bounds), is the addition of more photographs and diagrams to accompany
the text, especially in color.

Perhaps by the next edition of Sharing the Universe, Seth Shostak
won't have to fall back on explaining why aliens probably will not
want to steal Earth's water or try to stop us from destroying the rain
forests. Because if the public reads this book, they will be ready to
explore the real possibilities of extraterrestrial life through
science, our best tool and hope if we are ever to learn the answers to
all our questions about who and what is "out there".

The following are two Web sites with ordering information for Sharing
the Universe: